Microorganisms and isolated enzymes find wide use as a catalyst in the chemical industry or in food production. An overview is offered, for example, by: A. Liese, K. Seelbach, C. Wandrey, Industrial Biotransformations, Wiley-VCH: 2006, Weinheim, Germany.
In order to ensure economic use of such biocatalysts, some conditions have to be satisfied: the biocatalyst has to be active for a sufficiently long time under the reaction conditions, it should be readily removable after the end of the reaction and it should be reusable as often as possible. Ideally, these conditions should be satisfied for a very wide range of reaction conditions (for example temperature range, type of solvents used, pressures, etc.), in order to provide as universal as possible a catalyst.
In order to satisfy these conditions, it is typically necessary to immobilize the enzymes or microorganisms comprising the enzymes used.
Frequently, the enzymes or microorganisms comprising the enzymes are immobilized noncovalently on supports; the supports used are frequently ion exchange resins or polymer particles which possess suitable particle size distributions. Examples for this purpose are the commercial products Novozym 435, Lipozym RM IM or Lipozym TL IM from Novozymes A/S, Bagsvaerd, Denmark or Amano PS, from Amano, Japan. These examples are immobilized lipases which find wide use, since such immobilizates also exhibit industrially utilizable activities in nonaqueous systems, i.e., those which comprise only organic solvents, if any, as described, for example, in J. Chem. Soc., Chem. Comm. 1989, 934-935.
Patent Application DE 10 2007 031689.7 describes the various disadvantages of presently available immobilization technologies, in particular and with regard to activity and stability.